With energy costs continuing to rise, an ever-present need has developed for less expensive and more powerful reusable energy sources. As an example, wind-up power sources, which are typically wound manually by an operator, have been developed to provide inexpensive and portable mechanical or electrical power. Hand-cranked portable lights and radios have been developed that couple a handle to a generator for providing power to run an electrical device. However, many of such devices have no mechanism for storing mechanical power, so the handle must be turned continuously during use of the device.
Other designs have been developed to store mechanical energy for later use, thereby enabling a device to be used without continuous manual power. For example, U.S. Pat. No. 3,099,402 to Speck discloses a portable flashlight in which a spring motor having a pair of spiral or coiled springs drives a generator for lighting a bulb and charging a storage battery. A handle coupled to a pawl mechanism is used to wind the spring motor. Once wound up, the spring motor operates for a period of time to charge the battery and light the bulb.
However, the coiled springs in Speck are wound in the same direction and are housed in individual driving wheels which in effect couple the outer end of the first spring to the inner end of the second. A complex series of specifically designed gears and housings couple the springs to one another and to the generator. It has been found that this arrangement is unduly large and expensive given the additional mechanical components needed to couple the coiled springs together. Further, the two coiled springs in the disclosed arrangement are limited in the amount of power they can supply, thereby necessitating frequent rewinding.
Therefore, a significant need has continued to exist for a spring motor offering longer life in a smaller, less complex and less expensive package.
Another focus in the area of reusable energy sources is related to recapturing wasted energy in vehicles and the like. For example, wind-responsive systems have been developed to run a generator while a vehicle is moving. In addition, momentum-responsive systems may utilize a flywheel which is coupled to a vehicle's axles during coasting or braking to power a generator in response to vehicle momentum. In another system, relative movement of components (e.g., in an automobile's suspension) may be stored in a spring motor to subsequently power a generator. While all of these systems may recapture some wasted energy, a need nonetheless exists for improved recapture of wasted energy in a vehicle to thereby increase the efficiency of the vehicle.